The present invention relates generally to mobile communication networks, and, more particularly, to feedback information to user-terminals.
Present day communication networks with a grid of hubs (base-stations) serving multiple user-terminals (mobile stations or any other access-terminals), e.g. cellular networks, are often required to provide some measure of reception quality at the serving hub back to a user accessing the network. This feedback is typically used by the user terminal for periodically updating its transmission parameters in such a way that the overall communication network performance may be optimized. A particular selection of the transmission parameters at a user-terminal can also affect the link performances with the nearby hubs within the reception range of user's transmissions, in addition to the performance of the link with its serving hub. In the interest of overall optimization of the network performance, the selection of transmission parameters at the user terminal at any given time should be based on not only the reception quality at the serving hub, but also on the effects of its transmissions with the neighboring hubs within the reception range.
In a traditional communication network, all of the hubs within the reception range of the transmissions from a user-terminal are required to provide an estimation of the reception quality as perceived by them individually, directly to the user-terminal. This means that the user-terminal receives a feedback on the reception quality of its transmissions not only from the hub it is being served, but also from many other hubs in its vicinity. This requires the user-terminal to possess the ability to receive and process those multiple streams of the feedback information, in addition to the ability to receive and process the data and feedback received from the serving hub it is connected to. This capability is usually provided in the user-terminal by implementing more processing elements for the feedback from multiple hubs than needed to maintain the connection with the serving hub.
Implementation of extra elements requires additional hardware and software resources in the user-terminal. Besides, the receiver design of the user terminal will be more complicated because of the number of processing elements for the feedback information may vary as networks and locations may be different.
For instance, in High Rate Packet Data (HRPD) networks, which have a synchronous forward link and an asynchronous reverse link, the reverse-link power control is often influenced by multiple sectors or base-stations. In a typical scenario, a single base-station (or sector) serves the forward link to minimize the interference, while multiple base-stations (or sectors) serve the reverse link to gain from diversity. In such a system, the user-terminal receives the power-control bits from multiple base-stations (or sectors), while receiving the forward link data from a single base-station (or sector). This imposes an additional requirement in the user-terminal receiver design to handle the data and the power control bits separately, especially with a different number of processing elements.
As such, what is desired is a system and method to reduce the number of data streams received by a user terminal.